Basic support for operation with a home Node-B (HNB) or home evolved Node-B (HeNB) (hereinafter collectively referred to as HNBs) has been introduced into Release 8 of third generation partnership project (3GPP) specifications for wideband code division multiple access (WCDMA), long term evolution (LTE) and other cellular standards. An HNB is meant to be similar to the wireless local area network (WLAN) access point (AP), and is to be designed in a manner that allows access to cellular services to users over extremely small service areas, (e.g., homes or small offices). This may be useful in areas where cellular networks have not been deployed or legacy radio access technology (RAT) coverage exists, as well as in areas where cellular coverage may be faint or non-existent for radio related reasons, (e.g., underground metro or shopping mall). The subscriber (e.g., an individual or an organization), may deploy an HNB over an area where such service is desired.
An HNB may be deployed as a closed subscriber group (CSG) cell or a hybrid cell. A CSG cell is only accessible to members of the CSG. A hybrid cell is accessible to any wireless transmit/receive unit (WTRU), but may provide better or privileged service or quality of service (QoS) to members of the CSG.
FIG. 1 shows an example of a conventional HeNB deployment in a wireless communication system 100. The wireless communication system 100 includes an LTE macro-cell 105, a 3GPP system cell 110, a higher network node (e.g., gateway) 115 and/or a mobility management entity (MME)/serving general packet radio service (GPRS) support node (SGSN) 120. The higher network node 115 is responsible for coordinating the operation of several HeNBs 125A, 125B and 125C. Alternatively, the MME/SGSN 120 may be responsible for coordinating the operation of HeNBs 125A, 125B and 125C. The MME is the LTE equivalent of a 3G/2G SGSN. The relationship between the LTE macro-cell 105 and the 3GPP system 110, (e.g., WCDMA/global system for mobile communications (GSM)), is that there may be areas where the coverage of these two technologies overlap. This overlap in coverage is similar to simultaneous coverage of GSM and WCDMA technologies. The higher network node 115 is likely to be a gateway function which interfaces with the MME/SGSN 120. As a gateway, the role of the higher network node 115 may be to act as a single macro-cell towards the MME/SGSN 120 while supporting several small home cells.
FIG. 2 shows an LTE wireless communication system 200 including a WTRU 205, a serving CSG cell 210, and a neighbor CSG cell 215. To complete an inbound handover to a CSG cell in the LTE wireless communication system 200, the WTRU 205 needs to measure and report the CSG cell to the network. However, CSG cells are prone to physical layer cell identity (PCI) confusion, which is when two different CSG cells in the neighborhood of a radio network controller (RNC) or eNB, where the WTRU is initially connected, utilize the same PCI. PCI confusion may also exists if the WTRU has to handover to a CSG cell which it is not a member of (e.g., hybrid cell) A proposed solution has been for the WTRU to report the CSG cell global identity (CGI) to the network. Alternatively, another proposed solution is for the network to resolve the PCI confusion itself (i.e., map the PCI to the CGI), and then, if required, request the WTRU to report the CGI when handover occurs. But a reliable method and apparatus for resolving the PCI confusion is still desired.